Liebherr, a Switzerland-based crane and equipment manufacturer, is set to launch its new knuckle boom equipped RL-K 7500 sub-sea crane for the offshore industry.
The company said it will introduce the crane at its production plant in Rostock (Germany), in January 2013. RL-K 7500 with maximum rope diameter of 100 mm and maximum overturning moment of 75.000 kNm, can lift up to 290 tons in the air and handle loads to a water depth of 11,000 ft. Boom configuration can be enhanced for working radii of 165 ft.
The knuckle boom will enable the crane to lower loads in the water surface, using a short rope length between crane boom head and water line. Liebherr-Components has developed a gear ring rope winch for the RL-K 7500 offshore crane, which is specially designed for heavy lifting tasks at sea. With a tare weight of 200 tons the ZSW 2400 is the largest and heaviest rope winch offered by Liebherr. It is particularly noted for its high availability and long service life, which is reached by a redundant drive system and an innovative winding mechanism that protects the rope.
Liebherr has also fitted the crane with an Active Heave Compensation (AHC) system, based on advanced Motion Reference Units (MRUs).The AHC contain sensors to automatically identify and predict the vessel's motion and does not require manual adjustment. In order to provide up to 70% of the power required to operate the AHC system, the company has upgraded its hydraulic hybrid drive system Pactronic for sub-sea applications. A horizontal winch shifting system is also added to the subsea crane, to ensure the perfect fleet angle of the rope under all load conditions in both hoisting and lowering operations.
Capable of hoisting loads of up to 260 tonnes (290 tons), the RL-K 7500 crane can be installed on board drill vessels and heavy lift vessels. The knuckle boom can also be equipped with an Arctic temperature package to operate at -40 degrees Celsius temperature.
Sources: Energy Business Review, Subsea World News
